cmd/compile: include typecheck information in export/import

Include type information on exported function bodies, so that the
importer does not have to re-typecheck the body. This involves
including type information in the encoded output, as well as
avoiding some of the opcode rewriting and other changes that the
old exporter did assuming there would be a re-typechecking pass.

This CL could be considered a cleanup, but is more important than that
because it is an enabling change for generics. Without this CL, we'd
have to upgrade the current typechecker to understand generics. With
this CL, the current typechecker can mostly go away in favor of the
types2 typechecker.

For now, inlining of functions that contain closures is turned off.
We will hopefully resolve this before freeze.

Object files are only 0.07% bigger.

Change-Id: I85c9da09f66bfdc910dc3e26abb2613a1831634d
Reviewed-on: https://go-review.googlesource.com/c/go/+/301291
Trust: Keith Randall <khr@golang.org>
Trust: Dan Scales <danscales@google.com>
Reviewed-by: Dan Scales <danscales@google.com>

1 files changed, 309 insertions, 62 deletions

diff --git a/src/cmd/compile/internal/typecheck/iimport.go b/src/cmd/compile/internal/typecheck/iimport.go
index 35a1a0083a..0d5d892ef5 100644
--- a/src/cmd/compile/internal/typecheck/iimport.go
+++ b/src/cmd/compile/internal/typecheck/iimport.go
@@ -466,21 +466,6 @@ func (r *importReader) ident(selector bool) *types.Sym {
 func (r *importReader) localIdent() *types.Sym { return r.ident(false) }
 func (r *importReader) selector() *types.Sym   { return r.ident(true) }
 
-func (r *importReader) exoticSelector() *types.Sym {
-	name := r.string()
-	if name == "" {
-		return nil
-	}
-	pkg := r.currPkg
-	if types.IsExported(name) {
-		pkg = types.LocalPkg
-	}
-	if r.uint64() != 0 {
-		pkg = r.pkg()
-	}
-	return pkg.Lookup(name)
-}
-
 func (r *importReader) qualifiedIdent() *ir.Ident {
 	name := r.string()
 	pkg := r.pkg()
@@ -516,6 +501,114 @@ func (r *importReader) typ() *types.Type {
 	return r.p.typAt(r.uint64())
 }
 
+func (r *importReader) exoticType() *types.Type {
+	switch r.uint64() {
+	case exoticTypeNil:
+		return nil
+	case exoticTypeTuple:
+		funarg := types.Funarg(r.uint64())
+		n := r.uint64()
+		fs := make([]*types.Field, n)
+		for i := range fs {
+			pos := r.pos()
+			var sym *types.Sym
+			switch r.uint64() {
+			case exoticTypeSymNil:
+				sym = nil
+			case exoticTypeSymNoPkg:
+				sym = types.NoPkg.Lookup(r.string())
+			case exoticTypeSymWithPkg:
+				pkg := r.pkg()
+				sym = pkg.Lookup(r.string())
+			default:
+				base.Fatalf("unknown symbol kind")
+			}
+			typ := r.typ()
+			f := types.NewField(pos, sym, typ)
+			fs[i] = f
+		}
+		t := types.NewStruct(types.NoPkg, fs)
+		t.StructType().Funarg = funarg
+		return t
+	case exoticTypeRecv:
+		var rcvr *types.Field
+		if r.bool() { // isFakeRecv
+			rcvr = fakeRecvField()
+		} else {
+			rcvr = r.exoticParam()
+		}
+		return r.exoticSignature(rcvr)
+	case exoticTypeRegular:
+		return r.typ()
+	default:
+		base.Fatalf("bad kind of call type")
+		return nil
+	}
+}
+
+func (r *importReader) exoticSelector() *types.Sym {
+	name := r.string()
+	if name == "" {
+		return nil
+	}
+	pkg := r.currPkg
+	if types.IsExported(name) {
+		pkg = types.LocalPkg
+	}
+	if r.uint64() != 0 {
+		pkg = r.pkg()
+	}
+	return pkg.Lookup(name)
+}
+
+func (r *importReader) exoticSignature(recv *types.Field) *types.Type {
+	var pkg *types.Pkg
+	if r.bool() { // hasPkg
+		pkg = r.pkg()
+	}
+	params := r.exoticParamList()
+	results := r.exoticParamList()
+	return types.NewSignature(pkg, recv, nil, params, results)
+}
+
+func (r *importReader) exoticParamList() []*types.Field {
+	n := r.uint64()
+	fs := make([]*types.Field, n)
+	for i := range fs {
+		fs[i] = r.exoticParam()
+	}
+	return fs
+}
+
+func (r *importReader) exoticParam() *types.Field {
+	pos := r.pos()
+	sym := r.exoticSym()
+	off := r.uint64()
+	typ := r.exoticType()
+	ddd := r.bool()
+	f := types.NewField(pos, sym, typ)
+	f.Offset = int64(off)
+	if sym != nil {
+		f.Nname = ir.NewNameAt(pos, sym)
+	}
+	f.SetIsDDD(ddd)
+	return f
+}
+
+func (r *importReader) exoticSym() *types.Sym {
+	name := r.string()
+	if name == "" {
+		return nil
+	}
+	var pkg *types.Pkg
+	if types.IsExported(name) {
+		pkg = types.LocalPkg
+	} else {
+		pkg = r.pkg()
+	}
+	return pkg.Lookup(name)
+}
+
 func (p *iimporter) typAt(off uint64) *types.Type {
 	t, ok := p.typCache[off]
 	if !ok {
@@ -815,6 +908,11 @@ func (r *importReader) funcBody(fn *ir.Func) {
 		// functions).
 		body = []ir.Node{}
 	}
+	if go117ExportTypes {
+		ir.VisitList(body, func(n ir.Node) {
+			n.SetTypecheck(1)
+		})
+	}
 	fn.Inl.Body = body
 
 	r.curfn = outerfn
@@ -942,7 +1040,8 @@ func (r *importReader) expr() ir.Node {
 
 // TODO(gri) split into expr and stmt
 func (r *importReader) node() ir.Node {
-	switch op := r.op(); op {
+	op := r.op()
+	switch op {
 	// expressions
 	// case OPAREN:
 	// 	unreachable - unpacked by exporter
@@ -964,7 +1063,16 @@ func (r *importReader) node() ir.Node {
 		return n
 
 	case ir.ONONAME:
-		return r.qualifiedIdent()
+		n := r.qualifiedIdent()
+		if go117ExportTypes {
+			n2 := Resolve(n)
+			typ := r.typ()
+			if n2.Type() == nil {
+				n2.SetType(typ)
+			}
+			return n2
+		}
+		return n
 
 	case ir.ONAME:
 		return r.localName()
@@ -1028,64 +1136,145 @@ func (r *importReader) node() ir.Node {
 
 		return clo
 
-	// case OPTRLIT:
-	//	unreachable - mapped to case OADDR below by exporter
-
 	case ir.OSTRUCTLIT:
+		if go117ExportTypes {
+			pos := r.pos()
+			typ := r.typ()
+			list := r.fieldList()
+			n := ir.NewCompLitExpr(pos, ir.OSTRUCTLIT, nil, list)
+			n.SetType(typ)
+			return n
+		}
 		return ir.NewCompLitExpr(r.pos(), ir.OCOMPLIT, ir.TypeNode(r.typ()), r.fieldList())
 
-	// case OARRAYLIT, OSLICELIT, OMAPLIT:
-	// 	unreachable - mapped to case OCOMPLIT below by exporter
-
 	case ir.OCOMPLIT:
 		return ir.NewCompLitExpr(r.pos(), ir.OCOMPLIT, ir.TypeNode(r.typ()), r.exprList())
 
+	case ir.OARRAYLIT, ir.OSLICELIT, ir.OMAPLIT:
+		if !go117ExportTypes {
+			// unreachable - mapped to OCOMPLIT by exporter
+			goto error
+		}
+		pos := r.pos()
+		typ := r.typ()
+		list := r.exprList()
+		n := ir.NewCompLitExpr(pos, op, ir.TypeNode(typ), list)
+		n.SetType(typ)
+		if op == ir.OSLICELIT {
+			n.Len = int64(r.uint64())
+		}
+		return n
+
 	case ir.OKEY:
 		return ir.NewKeyExpr(r.pos(), r.expr(), r.expr())
 
 	// case OSTRUCTKEY:
 	//	unreachable - handled in case OSTRUCTLIT by elemList
 
-	// case OCALLPART:
-	//	unreachable - mapped to case OXDOT below by exporter
-
-	// case OXDOT, ODOT, ODOTPTR, ODOTINTER, ODOTMETH:
-	// 	unreachable - mapped to case OXDOT below by exporter
-
 	case ir.OXDOT:
 		// see parser.new_dotname
+		if go117ExportTypes {
+			base.Fatalf("shouldn't encounter XDOT in new importer")
+		}
 		return ir.NewSelectorExpr(r.pos(), ir.OXDOT, r.expr(), r.exoticSelector())
 
-	// case ODOTTYPE, ODOTTYPE2:
-	// 	unreachable - mapped to case ODOTTYPE below by exporter
+	case ir.ODOT, ir.ODOTPTR, ir.ODOTINTER, ir.ODOTMETH, ir.OCALLPART, ir.OMETHEXPR:
+		if !go117ExportTypes {
+			// unreachable - mapped to case OXDOT by exporter
+			goto error
+		}
+		pos := r.pos()
+		expr := r.expr()
+		sel := r.exoticSelector()
+		n := ir.NewSelectorExpr(pos, ir.OXDOT, expr, sel)
+		n.SetOp(op)
+		n.SetType(r.exoticType())
+		switch op {
+		case ir.ODOT, ir.ODOTPTR, ir.ODOTINTER, ir.OMETHEXPR:
+			n.Selection = r.exoticParam()
+			if op == ir.OMETHEXPR {
+				if r.bool() { // has name
+					ir.MethodExprName(n).SetType(r.exoticType())
+				}
+			}
+		case ir.ODOTMETH, ir.OCALLPART:
+			// These require a Lookup to link to the correct declaration.
+			rcvrType := expr.Type()
+			typ := n.Type()
+			n.Selection = Lookdot(n, rcvrType, 1)
+			if op == ir.OCALLPART {
+				// Lookdot clobbers the opcode and type, undo that.
+				n.SetOp(op)
+				n.SetType(typ)
+			}
+		}
+		return n
 
-	case ir.ODOTTYPE:
+	case ir.ODOTTYPE, ir.ODOTTYPE2:
 		n := ir.NewTypeAssertExpr(r.pos(), r.expr(), nil)
 		n.SetType(r.typ())
+		if go117ExportTypes {
+			n.SetOp(op)
+		}
 		return n
 
-	// case OINDEX, OINDEXMAP, OSLICE, OSLICESTR, OSLICEARR, OSLICE3, OSLICE3ARR:
-	// 	unreachable - mapped to cases below by exporter
-
-	case ir.OINDEX:
-		return ir.NewIndexExpr(r.pos(), r.expr(), r.expr())
+	case ir.OINDEX, ir.OINDEXMAP:
+		n := ir.NewIndexExpr(r.pos(), r.expr(), r.expr())
+		if go117ExportTypes {
+			n.SetOp(op)
+			n.SetType(r.typ())
+			if op == ir.OINDEXMAP {
+				n.Assigned = r.bool()
+			}
+		}
+		return n
 
-	case ir.OSLICE, ir.OSLICE3:
+	case ir.OSLICE, ir.OSLICESTR, ir.OSLICEARR, ir.OSLICE3, ir.OSLICE3ARR:
 		pos, x := r.pos(), r.expr()
 		low, high := r.exprsOrNil()
 		var max ir.Node
 		if op.IsSlice3() {
 			max = r.expr()
 		}
-		return ir.NewSliceExpr(pos, op, x, low, high, max)
-
-	// case OCONV, OCONVIFACE, OCONVNOP, OBYTES2STR, ORUNES2STR, OSTR2BYTES, OSTR2RUNES, ORUNESTR:
-	// 	unreachable - mapped to OCONV case below by exporter
+		n := ir.NewSliceExpr(pos, op, x, low, high, max)
+		if go117ExportTypes {
+			n.SetType(r.typ())
+		}
+		return n
 
-	case ir.OCONV:
-		return ir.NewConvExpr(r.pos(), ir.OCONV, r.typ(), r.expr())
+	case ir.OCONV, ir.OCONVIFACE, ir.OCONVNOP, ir.OBYTES2STR, ir.ORUNES2STR, ir.OSTR2BYTES, ir.OSTR2RUNES, ir.ORUNESTR:
+		if !go117ExportTypes && op != ir.OCONV {
+			// 	unreachable - mapped to OCONV case by exporter
+			goto error
+		}
+		return ir.NewConvExpr(r.pos(), op, r.typ(), r.expr())
 
 	case ir.OCOPY, ir.OCOMPLEX, ir.OREAL, ir.OIMAG, ir.OAPPEND, ir.OCAP, ir.OCLOSE, ir.ODELETE, ir.OLEN, ir.OMAKE, ir.ONEW, ir.OPANIC, ir.ORECOVER, ir.OPRINT, ir.OPRINTN:
+		if go117ExportTypes {
+			switch op {
+			case ir.OCOPY, ir.OCOMPLEX:
+				n := ir.NewBinaryExpr(r.pos(), op, r.expr(), r.expr())
+				n.SetType(r.typ())
+				return n
+			case ir.OREAL, ir.OIMAG, ir.OCAP, ir.OCLOSE, ir.OLEN, ir.ONEW, ir.OPANIC:
+				n := ir.NewUnaryExpr(r.pos(), op, r.expr())
+				if op != ir.OPANIC {
+					n.SetType(r.typ())
+				}
+				return n
+			case ir.OAPPEND, ir.ODELETE, ir.ORECOVER, ir.OPRINT, ir.OPRINTN:
+				n := ir.NewCallExpr(r.pos(), op, nil, r.exprList())
+				if op == ir.OAPPEND {
+					n.IsDDD = r.bool()
+				}
+				if op == ir.OAPPEND || op == ir.ORECOVER {
+					n.SetType(r.typ())
+				}
+				return n
+			}
+			// ir.OMAKE
+			goto error
+		}
 		n := builtinCall(r.pos(), op)
 		n.Args = r.exprList()
 		if op == ir.OAPPEND {
@@ -1093,18 +1282,37 @@ func (r *importReader) node() ir.Node {
 		}
 		return n
 
-	// case OCALLFUNC, OCALLMETH, OCALLINTER, OGETG:
-	// 	unreachable - mapped to OCALL case below by exporter
-
-	case ir.OCALL:
+	case ir.OCALL, ir.OCALLFUNC, ir.OCALLMETH, ir.OCALLINTER, ir.OGETG:
 		pos := r.pos()
 		init := r.stmtList()
 		n := ir.NewCallExpr(pos, ir.OCALL, r.expr(), r.exprList())
+		if go117ExportTypes {
+			n.SetOp(op)
+		}
 		*n.PtrInit() = init
 		n.IsDDD = r.bool()
+		if go117ExportTypes {
+			n.SetType(r.exoticType())
+			n.Use = ir.CallUse(r.uint64())
+		}
 		return n
 
 	case ir.OMAKEMAP, ir.OMAKECHAN, ir.OMAKESLICE:
+		if go117ExportTypes {
+			pos := r.pos()
+			typ := r.typ()
+			list := r.exprList()
+			var len_, cap_ ir.Node
+			if len(list) > 0 {
+				len_ = list[0]
+			}
+			if len(list) > 1 {
+				cap_ = list[1]
+			}
+			n := ir.NewMakeExpr(pos, op, len_, cap_)
+			n.SetType(typ)
+			return n
+		}
 		n := builtinCall(r.pos(), ir.OMAKE)
 		n.Args.Append(ir.TypeNode(r.typ()))
 		n.Args.Append(r.exprList()...)
@@ -1112,21 +1320,42 @@ func (r *importReader) node() ir.Node {
 
 	// unary expressions
 	case ir.OPLUS, ir.ONEG, ir.OBITNOT, ir.ONOT, ir.ORECV:
-		return ir.NewUnaryExpr(r.pos(), op, r.expr())
+		n := ir.NewUnaryExpr(r.pos(), op, r.expr())
+		if go117ExportTypes {
+			n.SetType(r.typ())
+		}
+		return n
 
-	case ir.OADDR:
-		return NodAddrAt(r.pos(), r.expr())
+	case ir.OADDR, ir.OPTRLIT:
+		n := NodAddrAt(r.pos(), r.expr())
+		if go117ExportTypes {
+			n.SetOp(op)
+			n.SetType(r.typ())
+		}
+		return n
 
 	case ir.ODEREF:
-		return ir.NewStarExpr(r.pos(), r.expr())
+		n := ir.NewStarExpr(r.pos(), r.expr())
+		if go117ExportTypes {
+			n.SetType(r.typ())
+		}
+		return n
 
 	// binary expressions
 	case ir.OADD, ir.OAND, ir.OANDNOT, ir.ODIV, ir.OEQ, ir.OGE, ir.OGT, ir.OLE, ir.OLT,
 		ir.OLSH, ir.OMOD, ir.OMUL, ir.ONE, ir.OOR, ir.ORSH, ir.OSUB, ir.OXOR:
-		return ir.NewBinaryExpr(r.pos(), op, r.expr(), r.expr())
+		n := ir.NewBinaryExpr(r.pos(), op, r.expr(), r.expr())
+		if go117ExportTypes {
+			n.SetType(r.typ())
+		}
+		return n
 
 	case ir.OANDAND, ir.OOROR:
-		return ir.NewLogicalExpr(r.pos(), op, r.expr(), r.expr())
+		n := ir.NewLogicalExpr(r.pos(), op, r.expr(), r.expr())
+		if go117ExportTypes {
+			n.SetType(r.typ())
+		}
+		return n
 
 	case ir.OSEND:
 		return ir.NewSendStmt(r.pos(), r.expr(), r.expr())
@@ -1134,6 +1363,11 @@ func (r *importReader) node() ir.Node {
 	case ir.OADDSTR:
 		pos := r.pos()
 		list := r.exprList()
+		if go117ExportTypes {
+			n := ir.NewAddStringExpr(pos, list)
+			n.SetType(r.typ())
+			return n
+		}
 		x := list[0]
 		for _, y := range list[1:] {
 			x = ir.NewBinaryExpr(pos, ir.OADD, x, y)
@@ -1149,8 +1383,8 @@ func (r *importReader) node() ir.Node {
 		stmts.Append(ir.NewAssignStmt(n.Pos(), n, nil))
 		return ir.NewBlockStmt(n.Pos(), stmts)
 
-	// case OAS, OASWB:
-	// 	unreachable - mapped to OAS case below by exporter
+	// case OASWB:
+	// 	unreachable - never exported
 
 	case ir.OAS:
 		return ir.NewAssignStmt(r.pos(), r.expr(), r.expr())
@@ -1165,11 +1399,12 @@ func (r *importReader) node() ir.Node {
 		}
 		return n
 
-	// case OAS2DOTTYPE, OAS2FUNC, OAS2MAPR, OAS2RECV:
-	// 	unreachable - mapped to OAS2 case below by exporter
-
-	case ir.OAS2:
-		return ir.NewAssignListStmt(r.pos(), ir.OAS2, r.exprList(), r.exprList())
+	case ir.OAS2, ir.OAS2DOTTYPE, ir.OAS2FUNC, ir.OAS2MAPR, ir.OAS2RECV:
+		if !go117ExportTypes && op != ir.OAS2 {
+			// unreachable - mapped to case OAS2 by exporter
+			goto error
+		}
+		return ir.NewAssignListStmt(r.pos(), op, r.exprList(), r.exprList())
 
 	case ir.ORETURN:
 		return ir.NewReturnStmt(r.pos(), r.exprList())
@@ -1241,6 +1476,10 @@ func (r *importReader) node() ir.Node {
 			"\t==> please file an issue and assign to gri@", op, int(op))
 		panic("unreachable") // satisfy compiler
 	}
+error:
+	base.Fatalf("cannot import %v (%d) node\n"+
+		"\t==> please file an issue and assign to khr@", op, int(op))
+	panic("unreachable") // satisfy compiler
 }
 
 func (r *importReader) op() ir.Op {
@@ -1253,7 +1492,11 @@ func (r *importReader) op() ir.Op {
 func (r *importReader) fieldList() []ir.Node {
 	list := make([]ir.Node, r.uint64())
 	for i := range list {
-		list[i] = ir.NewStructKeyExpr(r.pos(), r.selector(), r.expr())
+		x := ir.NewStructKeyExpr(r.pos(), r.selector(), r.expr())
+		if go117ExportTypes {
+			x.Offset = int64(r.uint64())
+		}
+		list[i] = x
 	}
 	return list
 }
@@ -1270,5 +1513,9 @@ func (r *importReader) exprsOrNil() (a, b ir.Node) {
 }
 
 func builtinCall(pos src.XPos, op ir.Op) *ir.CallExpr {
+	if go117ExportTypes {
+		// These should all be encoded as direct ops, not OCALL.
+		base.Fatalf("builtinCall should not be invoked when types are included in inport/export")
+	}
 	return ir.NewCallExpr(pos, ir.OCALL, ir.NewIdent(base.Pos, types.BuiltinPkg.Lookup(ir.OpNames[op])), nil)
 }